Attachment for engineers&#39; transits.



C'. M. PIDGEON.

ATTACHMENT FOR ENGINEERS' TRANSTTS.

APPLICATION. FILED FEB. 23, 1915.

Patented Dec. 12, 1916.

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",CHARLES PIDGEON, 0F WASHINGTON, DISTRICT OF COLUMBIA.

' ATTACHMENT FOR ENGINEERS TRNSITS.

Application filed February 2331915. Serial No.

To all Awhom t may concern.'

Be it known that l, CHARLES M. PIDGEON, a citizen of the United States, residing at Washington, vented certain new and usefullmprovements in Attachments for Engineers Transits; and ll do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others vskilled in the art to which it appertains to make and use the same.

My invention relates to'new and useful improvements in attachments for engineerstransits, alidades and other engineering and surveying instruments having a telescopic line of sight,`.and my prime object is to provide means .for mechanically determining and locating a meridian line by observation on the sun.

A further object is to so construct thedevice that. it will readily fit over the portion ofthe telescope carrying the objective lens. A further object is to so construct and position the reflector that it will not interfere with the use of the telescope for other purposes. And a further object is to so constructjthe attachment 4that it can be readily appliedto use without materially adding to the weight of the instrument and one that will dispense with the usual form of auxily-iary telescopes or other added means for observing thesun.

Other objects and advantages will be hereinafter set forth and more particularly pointed out in the accompanying specification. ln'the accompanying drawings which are made a part of this application, Figure 1 is a detailed elevation partly in section of an4 engineers transit, showing my improved device attached thereto. Fig. 2 1s an end elevation of the telescope, showing the attachment thereon.` F ig. 3 is a central longitudinal sectional view through the telescope and attachment, and Fig. 4 is a detailed elevation of a portion of the telescope, showing the manner of securing the attachment thereto. 1 Referring to the drawings in which similar reference numerals designate corresponding parts throughout the several views, 1 indicates a portion of the frame of a translt, which is constructed in the usual or any preferred manner, and 2 indicates the vusual form of telescope used in connection withA Specification of Letters Patent.

District of Columbia, have inl encumbering the instrument as lreflector is Patented Dec. 12, 1916.

the transit, said telescope having a'pivotal connection 3with the frame so that theobjectlve end 4 of the telescope may be raised or lowered as desire To determine a meridian byobservation on the sun, it has been customary heretofore to provide auxiliary telescopes and other devices in connection with the main telescopes' for observing the sun, well as adding welght thereto, and a multiplicity of 'adjustmg parts, therefore I have conceived a means of greatly simplifying the instrument as well as accomplishing the. desired result With the employment of fewer parts telescope of the instrument. To this end I 'thus greatly A provide a tubular sleeve .5 which extends H over the movable objective end 4 of the main telescopez the outer end of the sleeve finding a bearing upon the collar 6 at the outer end of the telescope, While the inner end of the sleeve finds a bearing upon. .the circumferential rib 7 on the stationary portion of the telescope, said rib having a circumferential groove 8 into which are introducedthe inner ends of screw or lugs 9 carried by the inner end of the sleeve 5, and by means of which the sleeve is held in engagement with vthe telescope and permitted to rotate thereon.

The length of the sleeve is such that when the objective end 4 of the telescope is eX- tended its full distance, the end of the sleeve is projected a short distance beyond the objective end and said projecting end has pivotally mounted therein a reflectorlO Which is adapted to direct the suns rays through the objective lens 11 and into the-telescope, 1

scope, 'so that the telescope may be used Ifor other purposes without interference from the reflector. From the point at which the ivota-lly mounted upon the sleeve, the en 'of the sleeve is cut at an angle of substantially 25, so that the suns rays will alivays strike the reflector even When turned to the extreme north declination.

The declination arm 13 has a graduated head or Vernier ifi, 'which cooperates with a graduated declination arc 15 to position the reflector'so that when the telescope is in the meridian and plunged to the latitude oi' the p..ace, the image of the sun will be re- 'lected in the center of the eld of the telescope. thereto an adjusting screw 16, which cooperates With a threaded sleeve 17 carried by the declination arm 13 so that said arm may be held in ladjustment with respect to the declination arc.

the sun, one face oit' the rib 7 is provided with graduations to 'form an hour arcor circle 18, With which cooperates a graduated index 19 on the sleeve 5, so that by ascertaining the time and rotating the slve until the index graduation registers with the proper hour graduations, the reflector will be positioned for bringing the image of the sun into the eld of the telescope when the telescope is swung onto a meridian and plunged to the latitude of the place.'

In operation, the latitude ot the place or observer is set oil1 on arcs provided on` the transit, to bring the line of collimation of the telescope in the axis oi the earth, when j the declination o the sun is set off on the declination arc 15 through the medium of the declination arm 13, thus so positioning the reiiector that when the transit isloriented on its pivots the reflected image of the sun will fall in the center of the field of the telescope thus establishing the meridian line. Simultaneously with the movement of the transit, the sleeve 5 is revolved about the telescope to bring the index 19 to the proper position with relation to the hour arc 1S to indicate the proper time, .thus properly centering the image of the sun with respect to the field of the telescope,

y Then the parts are operated as above described, the meridian may be immediately and mechanically determined Without the necessity of calculating to obtain the proper result. z l

By attaching the sleeve as shown, the same I telescope is used in determining the declina tion of the sun as is used for obtaining the latitude and various other purposes, and by arranging the reflector in the manner shown, the telescope may be freely used Without the reflector interfering 'with the line of vision. lt will likewise be seenthat by placing the sleeve around the.l end ot the main telescope that' all auxiliary telescopes'. or other attachments and their adjusting-mechanisms are dispensed With, simplifying the linstrument as VWell as reducingl the cost and Weight thereof, And furthermore by attaching the sleeve in the manner shown,4said sleeve may be freely rotated independently One end-of the arc l5 vhas attached ln order to readily ind .reducing the number ot parts employed for the various adjustments required in the other forms of telescopes constructed for this purpose.

lVhat I claim is l. The combination' with the objective end of a telescope, of means' mounted thereon to one side of the optical axis thereof and capable of adjustment in accordance with the time of day andthe position of the sun for projecting the image of the sun in the center line of the field of the telescope.

2. rlhe combination with the objective end of a telescope, of a sleeve mounted on said telescope and independently rotatableA thereon, a redactor upon the tree end of said sleeve, and means tor adjusting the position of the reflector in accordance with the time of day and the position of the sun.

3. The combination With a telescope, of a transit or other surveying instrument, havingva circumferentially grooved rib, of a sleeve adapted to fit over the objective end of said telescope, means carried by the sleeve engaging lsaid groove to hold the sleeve over said telescope, a reflector mounted at the free end of the sleeve, and means to adjust said reflector in accordance with the time of day and the position of the sun whereby the image of the sun will be reflected in the center of. the field of the telescope.

4. The combination with a transit telescope, having a grooved rib adjacent its pivot point, and a collar at its outer end, one edge of said rib having hour graduations thereon, of a sleeve adapted to fit over the objective end of the telescope and having its ends bearing respectively upon said rib and collar, means carried by the sleeve a graduated index to coperate with theQ hour graduations, a reflector pivoted in the free end of said sleeve,means to adjust said reflector in accordance with the time of day and the position of the sun to reflect the image of the sun in the center of the field of the telescope, said reflector being positioned to one side of the center of the field of the telescope.

5. The combination with a transit telescope, of a sleeve independently rotatably mounted upon one end oi the telescope, said sleeve having one of its ends projecting beyond the object end of the telescope, said end being cut at an angle to the axis of the sleeve, a reflector mounted in said projecting end,` and means to adjust said sleeve and reflector in accordance with 'the time of day and the position oil the sun to dect the' I rotatablyv attach the sleeve'to said instruf ment, a reflector pivotally mounted in the projecting portion of said sleeve, and means to adjust said reflector in accordance withl `10 the time of day and the position of the sun to refiect the image of the sun into the cen:

.ter of the field of the instrument.

In testimony whereof have signed my name to this specification in the presence of two subscribing Witnesses.

CHARLES M. PIDGEUN.

Witnesses:

D. W. Giu., MARK M. KELLEY.

Copies of this patent may be obtained for ve cents each, By addressing the Commissioner of Patents:

` Washington, D. E. 

